Descartes' Philosophy: Method, Doubt, and the Proof of God

René Descartes: Architect of Modern Rationalism

René Descartes was a prominent philosopher of the Early Modern period. For him, the idea of God is a metaphysical, innate, infinite, and rational concept. As a foundational rationalist philosopher, Descartes initiated modern philosophy by seeking a rigorous method to distinguish between truth and falsehood.

Descartes' Quest for Indubitable Truth: The Method

His method had to be universal, objective, and consisted of four rules:

• Evidence: To accept nothing as true unless it is clearly and distinctly evident, avoiding all prejudice and haste.
• Analysis: To divide each difficulty into as many parts as possible to resolve it better.
• Synthesis: To conduct thoughts in an orderly fashion, beginning with the simplest and most easily known objects, and ascending gradually to the knowledge of the more complex.
• Review: To make enumerations so complete and reviews so general that one is assured of omitting nothing.

Methodical Doubt and the Cogito

Having established this method, Descartes began to search within his consciousness for ideas that met the requirements of indubitable truths, much like those found in mathematics. To achieve this, he employed methodical doubt, systematically questioning all knowledge he possessed. Descartes famously reached the conclusion: 'Cogito, ergo sum' (I think, therefore I am). Even if he was mistaken about everything else, the very act of thinking confirmed his existence.

The Concept of Substance and God's Existence

In this sense, he identified himself as a thinking substance. He then proposed a second, superior substance: God. He understood substance as that which can exist independently, and specifically, God as that which necessarily exists. The idea of God, being infinite and perfect, is the only idea within him that could not have originated from his own finite self. Therefore, the origin or cause of this idea must be an infinite substance. The mere presence of this innate, infinite idea in his finite mind demonstrates that only an infinite being (God) could have placed it there.

The Innateness of Ideas and Divine Proof

This demonstration clearly resembles Anselm's ontological argument for God's existence, particularly in its reliance on the innateness of ideas. Descartes posited that human beings are born with a set of innate ideas, from which they build further knowledge. These fundamental ideas, discovered through reason, include:

• Thinking
• Existence
• Infinite Being

God as the Perfect Creator

Furthermore, Descartes recognized the existence of God through his own limitations and finitude. He reasoned that he could not have created himself. Since the perfections contained in the idea of God are clear, and as a finite being, he could not have endowed himself with all perfections, it follows that a being possessing all perfections must exist and have created him. Descartes ultimately defined God as the substance that exists by itself and is conceived through itself.